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Ion compaction effect in hollow FePt nanochains with ultrathin shell under low energy ion irradiation

Nano Research 2022年第10期15卷 9309-9318页

作者： Jialong Liu Jianguo Wu Long Cheng Suyun Niu Zhiqiang Wang Mengyuan Zhu jingyan zhang Shouguo Wang Wei Wang School of Mathematics and Physics Beijing University of Chemical TechnologyBeijing 100029China Key Laboratory of Shale Gas and Engineering Institute of Geology and GeophysicsChinese Academy of SciencesBeijing 100029China Innovation Academy for Earth Science Chinese Academy of SciencesBeijing 100029China School of Physics Beihang UniversityBeijing 100029China Beijing Hangxing Machinery Manufacturing Co. Ltd.Beijing 100013China Beijing Smart-chip Microelectronics Technology Co. Ltd.Beijing 100192China Beijing Advanced Innovation Center for Materials Genome Engineering School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China

The morphology manipulation of nanomaterials by ion irradiation builds a way to precisely control physicochemical properties.Under the continuous irradiation of low energy Ga+,Ne+,and He+ions,an ion compaction effect has been found in hollow FePt nanochains with ultrathin shell that the volumes of the nanochains are gradually compacted by ions.The deep learning algorithm has been successfully applied to automatically and precisely measure average sizes of spheres in hollow FePt nanochains.The compaction under ion irradiation is very fast in the very early period and then proceeds to a slow region.The compaction rates in both regions are linearly fitted and all the values are in the order of 10^(–17) to 10^(–14) cm^(2)/ion.Ion species and ion current have effect on the compaction rate.For example,the compaction rate of Ga+ions is larger than those of Ne+and He+ions under an identical current,while irradiation with larger current can compact nanochains faster.The ion compaction effect originates from the local shear deformation caused by the interaction between incident ions and the electrons of Fe and Pt atoms in the ultrathin shell.With continuous irradiation,the crystalline clusters of FePt nanchains firstly grow larger and then become amorphous.The ion compaction effect can be applied to tune the size and crystal structure of hollow structures with a precise rate by choosing appropriate ion species and current.

关键词： ion compaction effect hollow structure ion irradiation FePt

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Magnetoresistance anomaly in Fe_(5)GeTe_(2)homo-junctions induced by its intrinsic transition

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Nano Research 2023年第7期16卷 10443-10450页

作者： Ruijie Zhao Yanfei Wu Shaohua Yan Xinjie Liu He Huang Yang Gao Mengyuan Zhu Jianxin Shen Shipeng Shen Weifeng Xu Zeyu zhang Liyuan zhang jingyan zhang Xinqi Zheng Hechang Lei Ying zhang Shouguo Wang School of Materials Science and Engineering Beijing Advanced Innovation Center for Materials Genome EngineeringUniversity of Science and Technology BeijingBeijing 100083China Department of Physics and Beijing Key Laboratory of Opto-electronic Functional Materials&Micro-nano Devices Renmin University of ChinaBeijing 100872China School of Materials Science and Engineering Anhui UniversityHefei 230601China Institute of Advanced Materials Beijing Normal UniversityBeijing 100875China Beijing National Laboratory for Condensed Matter Physics and Institute of Physics Chinese Academy of SciencesBeijing 100190China

Two-dimensional van der Waals(2D vdW)magnets have attracted great attention recently and possess the unprecedented advantages of incorporating high-quality vdW heterostructures and homostructures into spintronic devices,and exploring various physical phenomena or technologies.Among them,Fe_(5)GeTe_(2)(F5GT)has ferromagnetic order close to room temperature,however the magnetic properties near its intrinsic transitions and F5GT-based 2D devices remain mostly unexplored.Here,we systematically demonstrate the peculiar magnetic properties of Fe_(5)GeTe_(2)nanoflakes near its intrinsic transition temperature(Tp)which is far lower than its Curie temperature(TC)of~265 K,and firstly discover anomalous magnetoresistance effect in F5GT homo-junctions by magneto-transport measurements.The strongest anomalous Hall effect occurs around Tp which is located in a temperature range from 130 to 160 K for the F5GT nanoflakes with different thicknesses.Furthermore,negative magnetoresistance(N-MR)and butterfly-shaped magnetoresistance(B-MR)are observed in F5GT homo-junction devices,and they appeared only in an intermediate temperature range from 110 to 160 K,noticeably showing the maxima near the T_(p)rather than the lowest temperature.Our experimental results clearly reveal the significant influence of intrinsic transitions on magnetic properties of F5GT and magnetoresistance effect in F5GT homo-junction devices,which imply a new strategy to achieve highperformance 2D spintronic devices by tuning intrinsic magnetic or structural transitions in 2D vdW magnets.

关键词： Two-dimensional(2D)van der Waals magnets Fe_(5)GeTe_(2) homo-junction magnetoresistance

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Greatly Enhanced Methanol Oxidation Reaction of CoPt Truncated Octahedral Nanoparticles by External Magnetic Fields

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Energy & Environmental Materials 2023年第5期6卷 201-210页

作者： Mengyuan Zhu Yi Wang Yanfei Wu Jialong Liu jingyan zhang He Huang Xinqi Zheng Jianxin Shen Ruijie Zhao Wenda Zhou Shouguo Wang Beijing Advanced Innovation Center for Materials Genome Engineering School of Materials Science and EngineeringUniversity of Science and Technology BeijingBeijing 100083China Department of Physics and Electronics School of Mathematics and PhysicsBeijing University of Chemical TechnologyBeijing 100029China

Tunable behavior in electrocatalysis by external multifields,such as magnetic field,thermal field,and electric field,is the most promising strategy to expand the theory,design,and synthesis of state-of-the-art catalysts and the cell in the near future.Here,a systematic investigation for the effect of external magnetic field and thermal field on methanol oxidation reactions(MOR)in magnetic nanoparticles is reported.For Co_(42)Pt_(58)truncated octahedral nanoparticles(TONPs),the catalytic performance in MOR is greatly increased to the maximum of 14.1%by applying a magnetic field up to 3000 Oe,and it shows a monotonical increase with increasing working temperature.The magnetic enhanced effect is closely related to the Co content of Co_(x)Pt_(100-x)TONPs.Furthermore,the enhancement effect under a magnetic field is more obvious for Co_(42)Pt_(58)TONPs annealed at 650℃.First-principle calculation points out that the magnetic fields can facilitate the dehydrogenation of both methanol and water by suppression of entropy of the electron spin and lowering of the activation barrier,where OH_(ad)intermediates on Co sites play a more important role.The application of magnetic fields together with thermal fields in MOR provides a new prospect to manipulate the performance of direct methanol fuel cells,which will accelerate their potential applications.

关键词： external magnetic fields first-principle calculation methanol oxidation reaction Pt-based magnetic nanomaterials

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Finding Critical Nuclei in Phase Transformations by Shrinking Dimer Dynamics and its Variants

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Communications in Computational Physics 2014年第8期16卷 781-798页

作者： Lei zhang jingyan zhang Qiang Du Beijing International Center for Mathematical Research Peking UniversityBeijing 100871China. Department of Mathematics Pennsylvania State UniversityPA 16802USA. Beijing Computational Science Research Center Beijing100084China.

We investigate the critical nuclei morphology in phase transformation by combining two effective ingredients,with the first being the phase field modeling of the relevant energetics which has been a popular approach for phase transitions and the second being shrinking dimer dynamics and its variants for computing saddle points and transition states.In particular,the newly formulated generalized shrinking dimer dynamics is proposed by adopting the Cahn-Hilliard dynamics for the generalized gradient system.As illustrations,a couple of typical cases are considered,including a generic system modeling heterogeneous nucleation and a specific material system modeling the precipitate nucleation in FeCr alloys.While the standard shrinking dimer dynamics can be applied to study the non-conserved case of generic heterogeneous nucleation directly,the generalized shrinking dimer dynamics is efficient to compute precipitate nucleation in FeCr alloys due to the conservation of concentration.Numerical simulations are provided to demonstrate both the complex morphology associated with nucleation events and the effectiveness of generalized shrinking dimer dynamics based on phase field models.

关键词： Critical nucleus phase field models saddle point shrinking dimer dynamics heterogeneous nucleation precipitate nucleation phase transformation

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革命传统教育融入初中地理教学——以“逆境中的奇迹——再看长征路上的地理困境”为例

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地理教学 2024年第11期 31-36页

作者：严光莹张晶妍南京市第十三中学锁金分校江苏南京210042

革命传统教育进课程可以促进国家与个人的发展以及教育体系的完善。地理学科可以从地理视角帮助学生理解革命传统。本文以“逆境中的奇迹——再看长征路上的地理困境”为例,明确教学目标、选取真实情境、搭建任务链,引导学生在尺度转换... 详细信息

革命传统教育进课程可以促进国家与个人的发展以及教育体系的完善。地理学科可以从地理视角帮助学生理解革命传统。本文以“逆境中的奇迹——再看长征路上的地理困境”为例,明确教学目标、选取真实情境、搭建任务链,引导学生在尺度转换以及今昔对比中分析问题,产生对革命传统的认同,为革命传统教育融入初中地理教学提供参考。

关键词：革命传统教育初中地理教学主题式教学

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Rechargeable Zn-air batteries initiated by nickel–cobalt bimetallic selenide

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Journal of Energy Chemistry 2019年第11期28卷 34-40页

作者： Changqi Sun Xiaosong Guo jingyan zhang Genliang Han Daqiang Gao Xiaoping Gao Key Laboratory of Sensor and Sensing Technology Gansu Academy of SciencesLanzhou 730000GansuChina College of Materials Science and Engineering Qingdao University of Science and TechnologyQingdao 266061ShandongChina Key Laboratory for Magnetism and Magnetic Materials of MOE Key Laboratory of Special Function Materials and Structure Design of MOELanzhou UniversityLanzhou 730000GansuChina

A Zn-air battery is a potential next-generation energy storage device owing to its extremely high theoretical energy density. Currently, it is important to explore non-precious metal electrocatalysts with high electroactivity and stability in the oxygen reduction reaction(ORR) and oxygen evolution reaction(OER) for the development of Zn-air batteries. In this work, porous(Ni,Co)Se2 nanosheets were synthesized by selenizing Ni Co2O4 nanosheets. By regulating the conductivity and morphology of the sample, the prepared porous(Ni,Co)Se2 nanosheets show enhanced electrocatalytic activity for OER and ORR compared to Ni Co2O4 nanosheets. The aqueous Zn-air battery using porous(Ni,Co)Se2 nanosheets as the air cathode exhibits superior charge and discharge performance(1.98 V for charging and 1.17 V for discharging), high specific capacity(770 m Ah/g), and excellent cycle stability(140 h). These results indicate that the porous(Ni,Co)Se2 nanosheets are suitable as a bifunctional electrocatalyst for future Zn-air batteries.

关键词： Electrocatalyst Zn-air batteries Oxygen evolution reaction Oxygen reduction reaction

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Precisely installing gold nanoparticles at the core/shell interface of micellar assemblies of triblock copolymers

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Chinese Chemical Letters 2017年第6期28卷 1276-1284页

作者： Kangning Zhu Zhiyuan Zhu Haiou Zhou jingyan zhang Shiyong Liu CAS Key Laboratory of Soft Matter Chemistry Hefei National Laboratory for Physical Sciences at the MicroscaleiChem(Collaborative Innovation Center of Chemistry for Energy Materials)Department of Polymer Science and EngineeringUniversity of Science and Technology of China School of Materials and Chemical Engineering Anhui Jianzhu University

Two reduction-cleavable ABA triblock copolymers possessing two disulfide linkages,PMMA-ssPMEO3MA-ss-PMMA and PDEA-ss-PEO-ss-PDEA were synthesized via facile substitution reactions from homopolymer precursors,where PMMA,PMEO3MA,PDEA,and PEO represent poly（methyl methacrylate）,poly（tri（ethylene glycol） monomethyl ether methacrylate,poly（2-（diethylamino）ethyl methacrylate）,and poly（ethylene oxide）,respectively.Spherical micelles were obtained through supramolecular self-assembly of these two triblock copolymers in aqueous solutions.The resultant micelles with abundant disulfide bonds could serve as soft templates and precisely accommodate gold nanoparticles in the core/shell interface as a result of the formation of Au-S bonds.

关键词： Triblock copolymer Disulfide bond Self-assembly Gold nanoparticle Core/shell interface

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“互联网+水产品贸易”跨境电商模式研究

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黑龙江水产 2024年第3期43卷 337-340页

作者：张靖妍辽宁现代服务职业技术学院辽宁沈阳110164

随着全球经济一体化进程的加快,跨境贸易已成为当前国际贸易的主要形式之一。水产品贸易作为其中重要的一部分,也受到了越来越多的关注。该研究旨在深入探讨“互联网+水产品贸易”跨境电商模式对水产品企业的影响和发展路径。通过对相... 详细信息

随着全球经济一体化进程的加快,跨境贸易已成为当前国际贸易的主要形式之一。水产品贸易作为其中重要的一部分,也受到了越来越多的关注。该研究旨在深入探讨“互联网+水产品贸易”跨境电商模式对水产品企业的影响和发展路径。通过对相关企业的案例研究和市场趋势的分析,揭示这一模式的关键特征和优势。研究发现,通过建立直采直供模式、多元化供应商合作、数字化营销和社交媒体推广,水产品企业能够在全球范围内实现市场拓展,提高产品的竞争力。

关键词： “互联网+水产品贸易” 跨境电商模式对策建议

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基于UPLC-Q-TOF-MS/MS技术分析香连丸的化学成分与小鼠体内的入血成分及代谢产物

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南京中医药大学学报 2024年第5期40卷 510-520页

作者：马嘉仪杨琰张竞研康安葛飞张琴南京中医药大学翰林学院附属海安市中医院江苏南通226600 南京中医药大学药学院江苏南京210023

目的采用UPLC-Q-TOF-MS/MS技术研究香连丸的体内外物质基础,对香连丸的主要成分、入血的原型成分及代谢产物进行定性分析。方法采用Thermo Accucore C_(18)柱(2.1 mm×100 mm,2.6μm),0.1%甲酸水(A)-乙腈(B)为流动相进行梯度洗脱,柱温40... 详细信息

目的采用UPLC-Q-TOF-MS/MS技术研究香连丸的体内外物质基础,对香连丸的主要成分、入血的原型成分及代谢产物进行定性分析。方法采用Thermo Accucore C_(18)柱(2.1 mm×100 mm,2.6μm),0.1%甲酸水(A)-乙腈(B)为流动相进行梯度洗脱,柱温40℃,流速为0.4 mL·min^(-1),进样量为4μL。采用电喷雾(ESI)离子源,正、负离子扫描模式下采集质谱信息。结果通过分析各成分的精确相对分子质量、保留时间、二级碎片等质谱信息,并与对照品的质谱信息和相关文献信息进行比对,最终在香连丸提取液中共鉴定出75个化学成分,主要为生物碱类、倍半萜类、黄酮苷类、柠檬苦素类和有机酸类等成分。此外,在给药后的小鼠血浆中共鉴定出16个原型成分和15个代谢产物。血浆中发现的原型成分以生物碱为主,这些成分在体内的代谢途径主要有羟基化、去甲基化、还原、水解、氢化和葡萄糖醛酸化等。结论该方法可用于快速且全面地鉴定香连丸的体内外化学成分,其分析结果为进一步阐明香连丸的药效物质基础提供依据。

关键词：香连丸 UPLC-Q-TOF-MS/MS 原型成分代谢产物生物碱类倍半萜

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数智时代档案学专业人才培养的需求、困境与进路——基于教师视角的调查

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档案学通讯 2024年第3期 104-112页

作者：许晓彤张婧妍张伟霞曲春梅山东大学历史学院济南250100

数字转型、智能升级背景下聚焦档案学专业人才培养关键需求与问题,有助于提高档案人才培养质量,提升档案智力支撑能力。通过文献研究、政策调研和问卷调查,梳理专业教师视角下数智时代档案学专业人才培养的概况、需求与困境,分析人才培... 详细信息

数字转型、智能升级背景下聚焦档案学专业人才培养关键需求与问题,有助于提高档案人才培养质量,提升档案智力支撑能力。通过文献研究、政策调研和问卷调查,梳理专业教师视角下数智时代档案学专业人才培养的概况、需求与困境,分析人才培养进路。来自全国28所高校的96名档案学专业教师参与调查。调查显示,档案学专业人才培养面临着技术要素融入与数据范式转型、档案资源深度挖掘与开发利用、提炼数智时代特色专业素养的迫切需求,同时需应对学生知识体系滞后于智能化时代趋势、专业能力难胜任档案资源深度开发需求、档案政策法规教育时代关照不足、数智素养基础不牢等现实困境。结合现实,需要从确立德才兼备的数智化档案人才培养目标、建设数据管理与数字人文课程生态、打造多学科背景专业教学团队、推动实践应用导向的项目制教学模式创新等方面着力,探索人才培养进路,促进档案学高等教育的转型升级与档案事业的高质量发展。

关键词：数智时代档案学人才培养

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